From: Ronnie Sahlberg lsahlber@redhat.com
[ Upstream commit ce465bf94b70f03136171a62b607864f00093b19 ]
RHBZ: 1649907
Fix a crash that happens while attempting to mount a DFS referral from the same server on the root of a filesystem.
Signed-off-by: Ronnie Sahlberg lsahlber@redhat.com Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/cifs/connect.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 0872188ce3c6..e508613f09ff 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -4459,11 +4459,13 @@ cifs_are_all_path_components_accessible(struct TCP_Server_Info *server, unsigned int xid, struct cifs_tcon *tcon, struct cifs_sb_info *cifs_sb, - char *full_path) + char *full_path, + int added_treename) { int rc; char *s; char sep, tmp; + int skip = added_treename ? 1 : 0;
sep = CIFS_DIR_SEP(cifs_sb); s = full_path; @@ -4478,7 +4480,14 @@ cifs_are_all_path_components_accessible(struct TCP_Server_Info *server, /* next separator */ while (*s && *s != sep) s++; - + /* + * if the treename is added, we then have to skip the first + * part within the separators + */ + if (skip) { + skip = 0; + continue; + } /* * temporarily null-terminate the path at the end of * the current component @@ -4526,8 +4535,7 @@ static int is_path_remote(struct cifs_sb_info *cifs_sb, struct smb_vol *vol,
if (rc != -EREMOTE) { rc = cifs_are_all_path_components_accessible(server, xid, tcon, - cifs_sb, - full_path); + cifs_sb, full_path, tcon->Flags & SMB_SHARE_IS_IN_DFS); if (rc != 0) { cifs_dbg(VFS, "cannot query dirs between root and final path, " "enabling CIFS_MOUNT_USE_PREFIX_PATH\n");